Rust-proofing process



w. H. ALLEN RUST PROOFING PROCESS Jan. 3,1928. 1,654,716

Filed May '7. 1926' TOR.

A TTORNEYL V as set out in the patent crystal growth of the phosphaterust Fatented Jan. 3, 1928.

PATENT OFFICE.

warm; 3. summer narnorr, MICHIGAN.

:cnsr-rnoorms rnocnss.

Application filed m s, 1926. serial No. 107,384.

The present invention relates to the treatment of ferrous metals toprotect them against rusting and relates specifically to improvements inrust proofing processes such to Coslett 870,937 of Nov. 12, 1907.

lln the practice of the Coslett process iron or steel articles arecontaining water, phosphoric acid andirfon 19 filings and allowed toremain for a time.

The articles in this treatment acquire coating of phosphate of ironwhichmilheres firmly and afiords protection. of the artiole against theoxidizingacti-on ofair'and moisture. p

In carrying out the outlined process on articles which are subsequentlyto be enameled, it has been found that such a1.- ticles especially metalsheets, frequently 29 have their surfaces so roughened by the coatingthat, when enameled, they do not present the desirable smooth polishedsurface. q It is among the objects of the present in- 29 ventio'ntherefore to prevent this rough deposit and produce rust proofedarticles which are quitesmooth on their surfaces and which. when*bsequently enameled shall present the characteristic smooth polishedsurface.

7 30 (Another object is means by which such operation may beaccomplished.

With these and other objects in view as will readily appear to thoseskilled in the art the invention consists in preventing pro ofing'composition and in means for carrying out such an operation.

Referring to the drawing, the figure is a more or less diagrammaticrepresentation,

40 one form of an apparatus by means of which the operation is carriedout. In the drawing, 1 indicates a tank or vat in which the solution ofwater phosphoric acid and iron filings is first boiled. Indicated at 2are metal sheets to be coated with the phosphate. These may be placed insuitable racks or cages (not shown) and are preferably evenly spacedasindicated.

' Above the tank 1 and adapted to be raised 59 and lowered is a frame 3carrying a series of rods 4 carrying at their lower ends padsplaced in aboiling bath or rolls 5 of material unafiected by the sol tion. Thesepads 5 will be long enough to extend the full width of the sheets 2 andlarge enough to rub lightly the adjacent surfaces of two sheets.

These pads or rolls are preferably of cotton cloth or covered with thismaterial but it is obvious other materials 'may be used. It is alsoobvious that other means than the specific apparatus shown may be usedfor the operation which consists in slowly and lightly rubbing thesurface of the article during the rust proofing treatfment. v 'L .Incarrying outthe improved process, the solution is first heated toboiling and the plates placed therein. Then while the heating iscontinued, the frame 3 is slowlymoved up and down until the coating hasprogressed to a suitable degree. The plates are thenremoved and dried.

Havingnow described the invention andt-h-e preferred form. of embodimentthereof it is to be understood that the said invention is not to belimitedto the specific details. herein described and shown but only bythe scope of the claims which follow.-

I claim 1. The process which consists in treating iron or steel articleswith a rust proofing solution adapted to form an iron compound upon thesurface of said articles and at the same timesubjecting said articles toa treatment to prevent crystal growth upon the said surfaces.

2. The process which consists in treating iron o1 steel articles witharust proofing solution adapted to form an iron phosphate upon same mentto prevent crystal growth upon the said surfaces. A

3.; The process which consists in treating iron or' steel articles withafrust proofing solution adapted to form an iron compound upon thesurface of said articles and at the same time rubbing lightly thesurfaces of the articles with pads of material inert to the solution andcoating.

wiLnIAM HELLER.

the surface of said articles and at the time subjecting said articles toa treat-

